Reader read(char[]) method in Java with Examples

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The read(char[]) method of Reader Class in Java is used to read the specified characters into an array. This method blocks the stream till:

It has taken some input from the stream.
Some IOException has occurred
It has reached the end of the stream while reading.

Syntax:

public int read(char[] charArray)

Parameters: This method accepts a mandatory parameter charArray which is the character array to be written in the Stream.

Return Value: This method returns an integer value which is the number of characters read from the stream. It returns -1 if no character has been read.

Exception: This method throws IOException if some error occurs while input-output. Below methods illustrates the working of read(char[]) method:

Program 1:

Java

// Java program to demonstrate
// Reader read(char[]) method
 
import java.io.*;
import java.util.*;
 
class GFG {
    public static void main(String[] args)
    {
 
        try {
 
            String str = "
            GeeksForGeeks& quot;
            ;
 
            // Create a Reader instance
            Reader reader = new StringReader(str);
 
            // Get the character array
            // to be read from the stream
            char[] charArray = new char[5];
 
            // Read the charArray
            // to this reader using read() method
            // This will put the str in the stream
            // till it is read by the reader
            reader.read(charArray);
 
            // Print the read charArray
            System.out.println(Arrays.toString(charArray));
 
            reader.close();
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

Output:

[G, e, e, k, s]

Program 2:

Java

// Java program to demonstrate
// Reader read(char[]) method
 
import java.io.*;
import java.util.*;
 
class GFG {
    public static void main(String[] args)
    {
 
        try {
 
            String str = "GeeksForGeeks";
 
            // Create a Reader instance
            Reader reader
                = new StringReader(str);
 
            // Get the character array
            // to be read from the stream
            char[] charArray
                = new char[str.length()];
 
            // Read the charArray
            // to this reader using read() method
            // This will put the str in the stream
            // till it is read by the reader
            reader.read(charArray);
 
            // Print the read charArray
            System.out.println(
                Arrays
                    .toString(charArray));
 
            reader.close();
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

Output:

[G, e, e, k, s, F, o, r, G, e, e, k, s]

Program 3:

Java

// Use a BufferedReader to read characters from the console.
import java.io.*;
 
public class GFG {
 
    public static void main(String args[])
        throws IOException
    {
        char c;
        BufferedReader br = new BufferedReader(
            new InputStreamReader(System.in));
        System.out.println(
            "Enter the characters: , 'q' to quit.");
 
        // read characters
        do {
            c = (char)br.read();
            System.out.println(c);
        } while (c != 'q');
    }
}